Race and gender differences in the use of medical treatments, and especially cardiac procedures, have been widely reported, but most studies do not explore why these differences exist. This project will examine whether physician decision making contributes to race and gender difference in patterns of medical care for coronary artery disease (CAD). Specifically, the project will assess the impact of patients' race and gender on physicians' estimate of disease probability and decisions to evaluate patients. The study hypotheses are that physicians underestimate the risks of CAD in blacks compared with whites and in women compared with men, and that physicians have higher thresholds for recommending diagnostic procedures in blacks compared with whites and in women compared with men. Case descriptions and a survey instrument will be developed using interactive video disc technology. Patients in the case descriptions will differ in their race, level of cardiovascular risk profile, and type of chest pain. Physicians will be recruited to participate in the study at national meetings of three specialties: family medicine, internal medicine, and cardiology. Each study physician will be shown a case description and will be asked to classify the type of pain reported by the patient, to estimate the prior probability of CAD, and whether to refer the patient for exercise stress testing. After receiving stress test results, the physician will be asked to estimate the posterior probability of CAD and whether to refer the patient for coronary angiography. Physicians' responses will be used to test the study hypotheses. This three-year project will be conducted by investigators at Georgetown University, with a subcontract to the University of Pennsylvania. The project will provide insight into the role of physician decision making in limiting access to cardiac procedures among blacks and women. In addition, the project will contribute to our understanding of the usefulness of a promising new technology-interactive videodiscs--in assessing the influence of patients characteristics on physicians' clinical decisions.